On 4/10/07, David Betz <dbetz at xlisper.com>
Thanks again! I have now successfully installed a
minimal RT-11 on
the RD54 of my PDP-11/73 system and it boots! Now I just have to
configure it with the programs I need (like DECUS C).
I guess RT-11 uses 512 byte blocks. My RD54 says
it holds around 64k
blocks. That's about 32mb.
That's the first partition.
What happened to the rest of the 150mb RD54?
It's still there, lurking.
Is it possible to put more than one partition on
the drive or
to convince RT-11 to use more than 32mb of the disk?
RT-11 uses, IIRC, 16-bit block pointers... 65536 x 512 bytes == 32MB,
the largest swath of a big drive it can grab in one chunk. I've never
personally run RT-11 with a disk over 32MB, so I don't know how it's
done, but I know it can be done. It might or might not depend on what
version of RT-11 you have. I *think* if you have MSCP support, you
always have the ability to have multiple partitions on your large
drives, but someone with experience on new(ish) hardware should chime
in. The largest machine I ever ran at home was an 11/23 with a couple
of RL drives. When I did use RT-11 on an 11/73 with a large disk, it
was under TSX-11, and without the docs in front of me, I'd hesitate to
quote technique from memory.
You should be able to find what you are looking for in the RT-11 docs
for versions of RT-11 > 5.4, at least. Dunno about < 5.4.
It is possible... I use an Emulex SCSI controller on my 11/23+ and it
works with multiple partition support via MSCP.
Each DU: driver can control several partitions (7?). It has to be
configured... Don't know how I did it. But I *think* there was something
about a "set" command.
The partitions on the drives (HDDs, CDROMs, ZIP) are sequential 32MB
blocks. Cool to use with SIMH images: "dd-compatible" :-)
The manual (?) mentioned the possibility to duplicate the DU: drivers
(i.e. copy du.sys to xx.sys etc.) in order to support more partitions.
But I had bad luck with that. The other issue was that I was not able to
boot from one another drive than DU0:
Good luck! If you have trouble, I can dig into the few runnable images I